A nine-year-old racehorse collapsed and died just minutes after winning the Toals Ulster Grand National yesterday (3 March), one of the biggest events in the Northern Irish horse racing calendar.

Chief Oscar, trained by Brian Hamilton and owned by Bobby Donaldson, had taken the lead five fences from the finish to claim the £16,000 first prize, but stumbled and fell as he was pulled up.

“There was no indication as he jumped the last fence in front that this drama would follow,” jockey Andrew Lynch told the Belfast Telegraph.

“I pulled him up after passing the winning post and it was only when cantering back to the start that he lost his rhythm and went down.”

Vets believe that the horse ruptured an artery and suffered a heart attack shortly after passing the finishing posts at the Downpatrick racecourse.

“There seems no obvious reason for it. The horse just ran his heart out. I have never known anything like it,” said Mr Lynch.

The trainer, Brian Hamilton, said: “It is a terrible way to end the day. I had always wanted to win the Ulster National, which is on my home ground, but it has ended in tragedy.”